Core-Shell Perovskite Quantum Dots for Highly Selective Room-Temperature Spin Light-Emitting Diodes.

Area of Science:

• Materials Science
• Optoelectronics
• Quantum Dot Technology

Background:

• Circularly polarized light (CPL) is vital for applications like magnetic recording and 3D displays.
• Perovskite quantum dots (QDs) offer tunable optoelectronic properties but require enhanced spin polarization for advanced applications.

Purpose of the Study:

• To develop core-shell heterostructured perovskite QDs for room-temperature spin-polarized light-emitting diodes (spin-LEDs).
• To leverage the chiral-induced spin selectivity (CISS) effect for efficient CPL emission.

Main Methods:

• Fabrication of 2D chiral perovskite shells on achiral 3D CsPbBr3 QD cores.
• Utilizing (R)- and (S)-1-(2-(naphthyl)ethylamine) (R-/S-NEA) chiral cations.
• Defect analysis and characterization of photoluminescence quantum yield (PLQY).
• Fabrication and testing of spin-LED devices and inkjet-printed patterns.

Main Results:

• Demonstrated CISS effect leading to spin-polarized carrier injection and CPL emission.
• Achieved high PLQY of 78% due to defect passivation by R-/S-NEA cations.
• Obtained maximum external quantum efficiency of 5.47% and a polarization degree (P_CP-EL) of 12% in spin-LEDs.
• Showcased inkjet-printable CPL-emitting patterns.

Conclusions:

• Core-shell perovskite QDs with chiral shells effectively generate CPL at room temperature.
• The developed spin-LEDs exhibit promising performance for next-generation display technologies.
• Chiral cation passivation is crucial for high PLQY and efficient spin polarization.